in response to mayer's original proposal: It is possible that we may change our policy on this in the future (because we are always discussing and tweaking how things work around here), but we currently do not have plans to change the downvoting requirement from a static number to a percent because no matter how old, reputable and/or experienced you are, there is no less of a chance for you to be wrong. As such, anyone should be able to point out that they think you are wrong, assuming they've been in the community for a short period of time. They are not required to make a comment with their downvote, but we do encourage it. We are working on significant UI design changes to promote this, but no matter the UI change, comments will still be optional.
As for anonymous downvotes, they will probably stay that way for the reasons that sterling mentioned. When in a democracy you are allowed to vote against anything without stating your reason, why should this be any different? You can state you have problems with the topic, and we provide a nice platform for that (comments) but you shouldn't be forced to show your opinion if you don't want to. But this is something that is being debated internally, and may be changed in the next few months.
As for malicious voting, if you are caught being malicious you will be banned from the site. Plain and simple. We have a pretty high tolerance for people here at iFixit, but if you are hurting the community in a noticeable way, [http://www.penny-arcade.com/comic/2010/2/24/|the ban hammer's fury will show no mercy.]
Side note, want to have a larger impact on iFixit's policies? [http://www.ifixit.com/info/jobs|We are hiring...]
